1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
use alloc::vec::Vec;
use indexmap::IndexSet;
use std::ops::{Deref, DerefMut};
use crate::common::{DebugLineStrOffset, DebugStrOffset, SectionId};
use crate::write::{BaseId, Result, Section, Writer};
// Requirements:
// - values are `[u8]`, null bytes are not allowed
// - insertion returns a fixed id
// - inserting a duplicate returns the id of the existing value
// - able to convert an id to a section offset
// Optional?
// - able to get an existing value given an id
//
// Limitations of current implementation (using IndexSet):
// - inserting requires either an allocation for duplicates,
// or a double lookup for non-duplicates
// - doesn't preserve offsets when updating an existing `.debug_str` section
//
// Possible changes:
// - calculate offsets as we add values, and use that as the id.
// This would avoid the need for DebugStrOffsets but would make it
// hard to implement `get`.
macro_rules! define_string_table {
($name:ident, $id:ident, $section:ident, $offsets:ident, $docs:expr) => {
#[doc=$docs]
#[derive(Debug, Default)]
pub struct $name {
base_id: BaseId,
strings: IndexSet<Vec<u8>>,
}
impl $name {
/// Add a string to the string table and return its id.
///
/// If the string already exists, then return the id of the existing string.
///
/// # Panics
///
/// Panics if `bytes` contains a null byte.
pub fn add<T>(&mut self, bytes: T) -> $id
where
T: Into<Vec<u8>>,
{
let bytes = bytes.into();
assert!(!bytes.contains(&0));
let (index, _) = self.strings.insert_full(bytes);
$id::new(self.base_id, index)
}
/// Return the number of strings in the table.
#[inline]
pub fn count(&self) -> usize {
self.strings.len()
}
/// Get a reference to a string in the table.
///
/// # Panics
///
/// Panics if `id` is invalid.
pub fn get(&self, id: $id) -> &[u8] {
debug_assert_eq!(self.base_id, id.base_id);
self.strings.get_index(id.index).map(Vec::as_slice).unwrap()
}
/// Write the string table to the `.debug_str` section.
///
/// Returns the offsets at which the strings are written.
pub fn write<W: Writer>(&self, w: &mut $section<W>) -> Result<$offsets> {
let mut offsets = Vec::new();
for bytes in self.strings.iter() {
offsets.push(w.offset());
w.write(bytes)?;
w.write_u8(0)?;
}
Ok($offsets {
base_id: self.base_id,
offsets,
})
}
}
};
}
define_id!(StringId, "An identifier for a string in a `StringTable`.");
define_string_table!(
StringTable,
StringId,
DebugStr,
DebugStrOffsets,
"A table of strings that will be stored in a `.debug_str` section."
);
define_section!(DebugStr, DebugStrOffset, "A writable `.debug_str` section.");
define_offsets!(
DebugStrOffsets: StringId => DebugStrOffset,
"The section offsets of all strings within a `.debug_str` section."
);
define_id!(
LineStringId,
"An identifier for a string in a `LineStringTable`."
);
define_string_table!(
LineStringTable,
LineStringId,
DebugLineStr,
DebugLineStrOffsets,
"A table of strings that will be stored in a `.debug_line_str` section."
);
define_section!(
DebugLineStr,
DebugLineStrOffset,
"A writable `.debug_line_str` section."
);
define_offsets!(
DebugLineStrOffsets: LineStringId => DebugLineStrOffset,
"The section offsets of all strings within a `.debug_line_str` section."
);
#[cfg(test)]
#[cfg(feature = "read")]
mod tests {
use super::*;
use crate::read;
use crate::write::EndianVec;
use crate::LittleEndian;
#[test]
fn test_string_table() {
let mut strings = StringTable::default();
assert_eq!(strings.count(), 0);
let id1 = strings.add(&b"one"[..]);
let id2 = strings.add(&b"two"[..]);
assert_eq!(strings.add(&b"one"[..]), id1);
assert_eq!(strings.add(&b"two"[..]), id2);
assert_eq!(strings.get(id1), &b"one"[..]);
assert_eq!(strings.get(id2), &b"two"[..]);
assert_eq!(strings.count(), 2);
let mut debug_str = DebugStr::from(EndianVec::new(LittleEndian));
let offsets = strings.write(&mut debug_str).unwrap();
assert_eq!(debug_str.slice(), b"one\0two\0");
assert_eq!(offsets.get(id1), DebugStrOffset(0));
assert_eq!(offsets.get(id2), DebugStrOffset(4));
assert_eq!(offsets.count(), 2);
}
#[test]
fn test_string_table_read() {
let mut strings = StringTable::default();
let id1 = strings.add(&b"one"[..]);
let id2 = strings.add(&b"two"[..]);
let mut debug_str = DebugStr::from(EndianVec::new(LittleEndian));
let offsets = strings.write(&mut debug_str).unwrap();
let read_debug_str = read::DebugStr::new(debug_str.slice(), LittleEndian);
let str1 = read_debug_str.get_str(offsets.get(id1)).unwrap();
let str2 = read_debug_str.get_str(offsets.get(id2)).unwrap();
assert_eq!(str1.slice(), &b"one"[..]);
assert_eq!(str2.slice(), &b"two"[..]);
}
}
|
